1. Field of the Invention
This invention relates to a thermographic printing machine and specifically, to a machine which applies a thermographic finish to matter printed by a conventional printer while the printed image is still wet.
2. Discussion of the Prior Art
Such machines have been well known for many years for printing individual sheet stock and individual cards. Attempts have been made to employ conventional machines to apply a thermographed image to continuous stationery as used for computers. This has proved to have various problems. These problems are mainly as follows:
1. It is difficult successfully to re-fold (fan-fold) the continuous paper after the thermographic treatment;
2. The shrinkage of the paper over a continuous length becomes significant and makes it difficult to recombine the thermographed paper into multi-part sets because the sprocket holes no longer line up;
3. It is impossible for a number of reasons to thermograph the continuous paper at a high enough speed. This is because the time taken to heat and then cool the thermographic `glaze` on the printing requires a certain minimum time, and this implies that , the faster the paper moves, the longer the machine. Machines up to 6 m. long have been tried.
The invention aims to overcome or ameliorate these problems.